Do reverse session cleanup in rpc_service_prepare_to_stop() instead.

Originally, the reverse session cleanup is called in rpc_service_stop().
But this leads to: create new foms, init these foms, and try to
queue these foms while the rpc service is stopped.
This will cause the reverse session can be not cleaned up.

Add delay of one second before doing fini in the UT to avoid
some pending requests/foms are still active.

Signed-off-by: Hua Huang <hua.huang@seagate.com>

rpc/service.c

@@ -67,7 +67,7 @@ static int rpc_service_start(struct m0_reqh_service *service)
 	return 0;
 }
 
-static void rpc_service_stop(struct m0_reqh_service *service)
+static void rpc_service_prepare_to_stop(struct m0_reqh_service *service)
 {
 	struct m0_rpc_service *svc;
 
@@ -76,6 +76,10 @@ static void rpc_service_stop(struct m0_reqh_service *service)
 	rev_conn_tlist_fini(&svc->rps_rev_conns);
 }
 
+static void rpc_service_stop(struct m0_reqh_service *service)
+{
+}
+
 static void rpc_service_fini(struct m0_reqh_service *service)
 {
 	struct m0_rpc_service *svc;
@@ -95,7 +99,8 @@ static const struct m0_reqh_service_ops rpc_ops = {
 	.rso_start      = rpc_service_start,
 	.rso_stop       = rpc_service_stop,
 	.rso_fini       = rpc_service_fini,
-	.rso_fop_accept = rpc_service_fop_accept
+	.rso_fop_accept = rpc_service_fop_accept,
+	.rso_prepare_to_stop = rpc_service_prepare_to_stop
 };
 
 static int rpc_service_allocate(struct m0_reqh_service **service,
@@ -266,7 +271,7 @@ m0_rpc_service_reverse_sessions_cleanup(struct m0_reqh_service *service)
 						   false);
 	} m0_tlist_endfor;
 	m0_tl_teardown(rev_conn, &svc->rps_rev_conns, revc) {
-		if (revc->rcf_disc_wait.cl_group != NULL) {
+		if (m0_clink_is_armed(&revc->rcf_disc_wait)) {
 			m0_chan_wait(&revc->rcf_disc_wait);
 			m0_clink_fini(&revc->rcf_disc_wait);
 		}

sns/cm/repair/ut/flock.c

@@ -265,6 +265,7 @@ static int test_setup(void)
 
 static int test_fini(void)
 {
+	m0_nanosleep(m0_time(1, 0), NULL);
 	m0_sns_cm_rm_fini(scm);
 	m0_cm_ast_run_thread_fini(cm);
 	cs_fini(&sctx);